Inlets for a double disc refiner

ABSTRACT

A double disc refiner apparatus for use in paper stock preparation and comprising two novel stock flow-conditioning inlet conduits. These inlet conduits impart a smooth, helical flow pattern to the stock being supplied to the double disc refiner. This pattern is imparted with minimum pressure drop and no material hang-up in the inlets. These inlets are both so constructed that the stock is caused to enter the refiner while spinning in the direction of rotor rotation and after receiving an axial or inward impetus from a helical configuration of the rear wall of the inlet compartment.

Muted States Patent 1191 1111 3,845,910

(Iledaniel Nov. 5, v1974 INLETS FOR A DOUBLE DISC REFINER 3,690,571 9/1972 Rudi 241/245 x Inventor: William Richard Cledaniel, 3,746,270 7/l973 Moore 24l/25l Andover Mass Primary ExaminerGranville Y. Custer, Jr. [73] Assignee: Bolton-Emerson, Inc., Lawrence, Assistant Examiner-Howard N. Goldberg Mass. 1221 Filed: Oct. 10, 1972 [57] ABSTRACT A double dlsc refiner apparatus for use in paper stock PP' NOJ 296,130 preparation and comprising two novel stock flowconditioning inlet conduits. These inlet conduits im- 52 US. e1 241/245, 241/1310, 5, 241/2612 P 11 Smooth, helical flow Pattern to the Stock being 151 1111. C1. B02 7/06, 1302c 23/02 supplied to the double disc refiner This Pattern is [58] Field of Search 241/244, 245, 248, 250, parted with minimum Pressure p and no material 4 25 2612,1316 5 5 141, 146 hang-up in the inlets. These inlets are both so constructed that the stock is caused to enter the refiner 5 References Cited while spinning in the direction of rotor rotation and UNITED STATES PATENTS after receiving an axial or inward impetus from a helical configuration of the rear wall of the inlet compart- 1,666,640 4/1928 Cunmff 241 245 2,058,175 10/1936 Pinkerton et al. 241/245 X 3,323,731 6/1967 Asplund et al 241/146 7 Claims, 3 Drawing Figures INLETS FOR A DOUBLE DISC REFINER BACKGROUND OF THE INVENTION Double disc refining of paper stock is well known in the paper-making art. Double disc refiners are normally characterized by a disc having refining blades on each side and rotating between a pair of stators. Paper stock is fed, in two streams, into the space between each side of a disc and a stator adjacent each side of the disc. For optimum operating efficiency, and the lowest maintenance cost, the flow of paper-making stock to each side of the disc should be well balanced. Moreover, the flow should be distributed uniformly about the inner (i.e., smaller) circumference of the refining plates mounted on the disc. As a consequence of these requirements, much design emphasis is placed onthe construction of the inlets to double disc refiners. The inlets should not be susceptible to plugging and should assure a minimum pressure drop within the inlet configuration and at the interface of the incoming stock and the refining disc itself.

LII

Noiinlet system heretofore known has fully achieved the desired characteristics. 1

SUMMARY OF THEINVENTION Therefore, it is a principal object of the instant invention to provide a. double disc refiner having'improved operating characteristics attributable to novel 'inlet flow-conditioning means associated therewith.

It isa further object of the invention to provide improved feed inlet means for a double disc refiner which inlet means impart very little pressure drop to the stock being transported therethrough' and which inlet means are self-flushing, thereby providing no pockets in which pulp fibers can deposit in such a way as to modify stock flow properties through the inlet means.

Another object of the invention is to provide improved inlet flow-conditining means for a double disc refiner which means impart an inward thrust to the paper stock simultaneously with a tangential flow vector.

The above objects have been substantially accomplished by providing a double disc refiner with two stock inlet means which are essentially of the same design, except that modifications are required in one of them to accommodate the drive shaft for a cantilevered refining disc. By same" design is meant that their flow-imparting characteristics are mirror images one of the other. Thus, flow entering the refiner from'two such inlets, one on either side of the disc, will be adapted to have a tangential velocity component in the same direction as the disc rotates.

Each comprises an inlet part, or conduit, which is tangentially arranged with respect to the port through which the inlet itself communicates with the refiner proper. Flow from this tangentially arranged conduit enters the inlet chamber and encounters a wall portion of the chamber which slopes towards the refiner proper, thereby imparting an axial thrust to the tangentially swirling inlet stream. This tangential swirl is imparted to be along the direction of rotation of the refining disc. I

The stock is then discharged through a 360 annular opening, which is arranged in register to the area proximate the inner circumference of the refining disc.

ILLUSTRATIVE EXAMPLE OF THE INVENTION In this application and accompanying drawings, there is shown and described a preferred embodiment of the invention, but it is to be understood that this is'not intended to be exhaustive and that other changes and modifications can be made within the scope of the invention. The suggestions herein are selected forfpurposes of illustration in order that others skilled in the art will more fully understand the invention and the principles thereof and will be able to modify it and embody it in a variety of forms, each as may be best suited in the condition of a particular case.

IN THE DRAWINGS FIG. 1 is a front elevation, partly schematic and partly in section, showing a double disc refiner constructed according to the invention;

FIG. 2 is a fragmentary view, similar to FIG. 1, showing the flow of stock through the approved stock inlet means;

FIG. 3 is an end elevation view looking from the refiner proper into the rightmost inlet of FIG. 2. Referring to FIG. 1, it is seen that a double disc refiner'l0 comprises a housing 12 for a rotor l4.and two stators 16 mounted inside housing 12 opposite the faces of rotor-14. Paper stock is admitted to each side of rotor 14 at the inner edge 18 of refining blades 20, and leaves'the refiner through annular chamber 22 and tangential outlet 24. Rotor 14 is positioned forrotation with shaft 26, which is mounted on bearings 28.

It will be seen that on each side of housing 12 is connected a stock inlet means 30 comprising a conduit 32 leading, tangentially, to a flow-conditioning chamber 34. Chamber 34 comprises a radially extending wall 36 which is of helical configuration and sloped toward the refiner disc. Wall 36 extends from the inner circumferential chamber wall formed by the cylindrical plug 38, which fills the central part of chamber 34, to the outer circumferential chamber wall 41 of chamber 34 and thereby assures that the velocity and circular motion of the stock initially imparted by the tangential conduit 32 is preserved during passage of the fluid through the in let, until the stock is discharged from the inlet in a 360 annular opening 42. Moreover, an axial velocity component is contributed to the stock by wall 36, as well as by the above mentioned circular velocity, thereby facilitating feed to the refiner disc.

The shaft packing box and bearings are advantageously housed within one of the inlets, as seen at 44, and this is accomplished without any undue interference with the flow design of the flow path through the inlet.-

Thus it is seen that the inlet box, and conduit leading thereto, form a self-flushing path for stock, wherein all of the structual elements forming the path play a helpful role in imparting useful motion to the stock being supplied to the double disc refiner.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

I claim:

1. In a double disc paper stock refiner having refining plates with an inner circumference mounted on the discs, the improvement wherein the stock supply means includes two flow-conditioning stock inlet means, each said stock inlet means being arranged to discharge stock in the same rotational direction and comprising:

an inlet conduit tangentially arranged with respect to a flow-conditioning chamber, said chamber having an inner, and an outer, circumferential wall;

a-helically-shaped wall forming the back wall of said chamber and forming means to impart circular and axial velocity to the stock coming into said chamber through said tangentially arranged conduit, said helically-shaped wall extending to the outer circumferential wall of said flow-conditioning chamber from the said inner circumferential wall of a centrally located plug member mounted axially in said flowconditioning chamber, and

an annular opening from said chamber into said paper stock refiner, said opening adapted to discharge paper stock proximate the said inner circumference of said refining plates.

2. A double disc paper stock refiner as defined in claim 1, wherein one said plug member houses a packing box for a shaft extending through said plug and forming means to rotate said disc.

3. A double disc paper stock refiner as defined in claim 1, wherein said flow-conditioning chambers are so positioned with respect to said refining disc as to form means to impart a rotational flow to the stock in the direction which the disc is adapted to rotate.

4. A double disc paper stock refiner as defined in claim 2, wherein said flow-conditioning chambers are so positioned with respect to said refining disc as to form means to impart a rotational flow to the stock in the direction which the disc is adapted to rotate.

5. A double disc paper stock refiner having a pair of opposed inlet means, each axially feeding through the center of one of the stators into the refining interface of the rotor and stators thereof;

each said inlet means including a generally cylindrical housing having a cylindrical plug concentrically spaced therewithin and forming an annular influent chamber, a sloping outer, or back, wall to said chamber of helical configuration and an inlet conduit leading tangentially into said annular chamber.

6. A refiner as specified in claim 5, wherein one said plug contains the shaft packing box, or gland, of said rotor.

7. A refiner as specified in claim 5, wherein said inlet means is free of ledges or shelves.

I :UNITED- STATES PATENT OFFICE CERTIFICATE OF CORRECTIQN Patent No 3 "-910 Dated November 5 2 1974 Inventor(s) William Richard Clendaniel It is certified that error appears in the above-identified patent and that said Lej;ters Patent are hereby corrected as shown below:

Thelhventofs surname Cledaniel should be I Clegdaniel. v

Signeda nd sealed this 14th clay of January 1975.

(SEAL) Arrest: I}

McCOY M. GIBSON JR. C. MARSHALL DAN N Arresting Officer Commissioner of Patents USCOMM-DC 60376-1 69 U.$. GOVERNMENT PRINTING OFFICE I969 O3G6-334 FORM PC4050 (10-69) 

1. In a double disc paper stock refiner having refining plates with an inner circumference mounted on the discs, the improvement wherein the stock supply means includes two flow-conditioning stock inlet means, each said stock inlet means being arranged to discharge stock in the same rotational direction and comprising: an inlet conduit tangentially arranged with respect to a flowconditioning chamber, said chamber having an inner, and an outer, circumferential wall; a helically-shaped wall forming The back wall of said chamber and forming means to impart circular and axial velocity to the stock coming into said chamber through said tangentially arranged conduit, said helically-shaped wall extending to the outer circumferential wall of said flow-conditioning chamber from the said inner circumferential wall of a centrally located plug member mounted axially in said flow-conditioning chamber, and an annular opening from said chamber into said paper stock refiner, said opening adapted to discharge paper stock proximate the said inner circumference of said refining plates.
 2. A double disc paper stock refiner as defined in claim 1, wherein one said plug member houses a packing box for a shaft extending through said plug and forming means to rotate said disc.
 3. A double disc paper stock refiner as defined in claim 1, wherein said flow-conditioning chambers are so positioned with respect to said refining disc as to form means to impart a rotational flow to the stock in the direction which the disc is adapted to rotate.
 4. A double disc paper stock refiner as defined in claim 2, wherein said flow-conditioning chambers are so positioned with respect to said refining disc as to form means to impart a rotational flow to the stock in the direction which the disc is adapted to rotate.
 5. A double disc paper stock refiner having a pair of opposed inlet means, each axially feeding through the center of one of the stators into the refining interface of the rotor and stators thereof; each said inlet means including a generally cylindrical housing having a cylindrical plug concentrically spaced therewithin and forming an annular influent chamber, a sloping outer, or back, wall to said chamber of helical configuration and an inlet conduit leading tangentially into said annular chamber.
 6. A refiner as specified in claim 5, wherein one said plug contains the shaft packing box, or gland, of said rotor.
 7. A refiner as specified in claim 5, wherein said inlet means is free of ledges or shelves. 